Aerodynamic rear drag reduction system for a trailer

ABSTRACT

A rear aerodynamic drag reduction system is configured to be coupled to a rear frame assembly of a trailer including a rear frame and a rear swing door. The rear drag reduction system includes a main wall panel configured to be coupled to the rear frame assembly to extend generally rearwardly of the trailer at least partially along a height of the trailer, and a secondary wall panel configured to be movably coupled to the rear swing door of the trailer to extend along a width of the trailer. The main wall panel and the secondary wall panel are each movable relative to the rear frame assembly between a deployed position and a stowed position. A locking mechanism of the drag reduction system is configured to releasably couple the main wall panel and the secondary wall panel to each other to prevent relative movement between the main wall panel and the secondary wall panel when the main and secondary wall panels are in their deployed positions.

This application claims priority under 35 U.S.C. §119(e) to U.S.Provisional Patent Application Ser. No. 61/993,306 entitled AERODYNAMICREAR DRAG REDUCTION SYSTEM FOR A TRAILER and filed May 15, 2014, theentirety of which is hereby incorporated by reference herein.

This application cross-references U.S. patent application Ser. No.14/049,506 entitled AERODYNAMIC REAR DRAG REDUCTION SYSTEM FOR A TRAILERand filed Oct. 9, 2013, the entirety of which is hereby incorporated byreference herein.

FIELD OF THE INVENTION

The present invention relates generally to semi-trailers, such asvan-type trailers, for example. In particular, the present inventionrelates to an aerodynamic rear tail system for reducing draft on such atrailer.

BACKGROUND OF THE INVENTION

To reduce wind flow resistance and drag on a trailer, truck,semitrailer, or other vehicle, side skirts which extend downwardly froma bottom of the trailer and/or chassis toward the roadway to partiallyenclose the floor assembly and undercarriage of the trailer, fairingsand other such structures have been used. Many structures associatedwith the rear of the trailer are provided in order to reduce theaerodynamic drag on the trailer.

A typical storage container of a trailer terminates with a large,rectangular rear surface. This shape causes an area of reduced pressureto be created behind the trailer storage container as it moves over thehighway, thus generating a slowing force that must be overcome withadditional engine power and thus additional fuel. In other words, airflow passing behind the vehicle imparts a drag force to the vehicle.Rear trailer fairings are designed to streamline the rear end of thetrailer in order to control the flow of air at the rear of the vehicle.Such reduction on the drag of the ground vehicle may operate to conservefossil fuels as well as other sources of vehicle drive power for hybridvehicles, battery-operated vehicles, and alternative fuel-basedvehicles, for example. However, many such fairings which cover the rearend of the trailer also may cover the rear doors of the trailer whichmust be opened and closed by a user to load and unload the cargo withinthe storage area of the trailer in such a way that users may be requiredto dismount and mount the fairing(s) each time a loading or unloadingoperation is to be performed.

SUMMARY

The present invention may comprise one or more of the features recitedin the attached claims, and/or one or more of the following features andcombinations thereof.

According to one aspect of the present disclosure, a rear aerodynamicdrag reduction system configured to be coupled to a rear frame assemblyof a trailer including a rear frame and a rear swing door includes amain wall panel, a secondary wall panel, and a locking mechanism. Themain wall panel is configured to be coupled to the rear frame assemblyto extend generally rearwardly of the trailer at least partially along aheight of the trailer. The main wall panel is movable relative to therear frame assembly between a deployed position and a stowed position.The secondary wall panel is configured to be movably coupled to the rearswing door of the trailer to extend generally rearwardly of the trailerat least partially along a width of the trailer. The secondary wallpanel is movable relative to the rear frame assembly between a deployedposition and a stowed position. The locking mechanism is configured toreleasably couple the main wall panel and the secondary wall panel toeach other to prevent relative movement between the main wall panel andthe secondary wall panel when the main and secondary wall panels are intheir deployed positions.

In one illustrative embodiment, the main wall panel and the secondarywall panel may each be configured to be pivotably coupled to the rearframe assembly. The secondary wall panel may be pivotably coupled to therear swing door of the rear frame assembly. Illustratively, the mainwall panel may be configured to be pivotably coupled to the rear swingdoor of the rear frame assembly, and the main wall panel may beconfigured to pivot about an axis offset from an axis about which therear swing door pivots. Alternatively, the main wall panel may beconfigured to be pivotably coupled to a vertical member of the rear fameof the rear frame assembly, and the main wall panel may be configured topivot about an axis aligned with an axis about which the rear swing doorpivots.

In another illustrative embodiment, the locking mechanism may include afirst portion coupled to the main wall panel and a second portioncoupled to the secondary wall panel. The first and second portions ofthe locking mechanism may be configured to releasably engage each other.

In still another illustrative embodiment, the locking mechanism mayinclude (i) a latch coupled to the one of the main wall panel and thesecondary wall panel, the latch defining a slot, and (ii) a pin coupledto the other of the main wall panel and the secondary wall panel.Illustratively, the pin may be received within the slot when the mainand secondary wall panels are in their deployed positions. Furtherillustratively, the latch may be coupled to an inner surface of thesecondary wall panel and the pin is coupled to an inner surface of themain wall panel. The latch may be positioned adjacent outer and bottomedges of the secondary wall panel and the pin may be positioned adjacentthe rear and top edges of the main wall panel. Illustratively, the pinmay include a head received within the slot when the main and secondarywall panels are in their deployed positions, and a body coupled to theinner surface of the main wall panel. Further illustratively, the bodyof the pin may include an upper portion offset from a lower portion. Thelatch may be integrally formed with the secondary wall panel and the pinmay be integrally formed with the main wall panel. As such, the latchmay illustratively extend downwardly below an inner surface of thesecondary wall panel and the pin may extend upwardly above a top edge ofthe main wall panel.

In yet another illustrative embodiment, the locking mechanism may beautomatically moved to a locked position when a user moves the rearswing door to a fully-closed position. Further, the locking mechanismmay be automatically moved to an unlocked position when a user moves therear swing door to a fully-opened position. Illustratively, the mainwall panel may also be automatically moved to the deployed position whena user moves the rear swing door to a fully-closed position, and themain wall panel may be automatically moved to the stowed position when auser moves the rear swing door to a fully-opened position.

According to another aspect of the present disclosure, a rearaerodynamic drag reduction system configured to be coupled to a rearframe assembly of a trailer including a rear frame and a rear swing doorincludes a main wall panel configured to be coupled to a vertical memberof the rear frame to extend generally rearwardly of the trailer at leastpartially along a height of the trailer, a secondary wall panelconfigured to be coupled to the rear swing door of the trailer to extendgenerally rearwardly of the trailer at least partially along a width ofthe trailer, and a locking mechanism having a first portion coupleddirectly to the main wall panel and a second portion coupled directly tothe secondary wall panel. The first and second portions of the lockingmechanism are coupled to each other when the main wall panel and thesecondary wall panel are configured to extend rearwardly of the trailer.

In one illustrative embodiment, the main wall panel may be movablebetween a deployed position and a stowed position. Illustratively, thesecondary wall panel may also be movable between a deployed position anda stowed position. Further illustratively, the main wall panel may beautomatically moved to the deployed position and the locking mechanismmay be automatically moved to a locked position when a user moves therear swing door to a fully-closed position. Illustratively, the firstand second portions of the locking mechanism may be automaticallyengaged with each other as the main and secondary wall panels are movedto the deployed position. Further, the first and second portions of thelocking mechanism may be automatically disengaged with each other as themain and secondary wall panels are moved to the stowed position.

In another illustrative embodiment, the secondary wall panel may includea first portion configured to be coupled to a top of the rear swing doorand a second portion pivotably coupled to the first portion for movementabout an axis parallel to a top edge of the rear swing door.

Illustratively, the second portion of the locking mechanism may becoupled to the second portion of the secondary wall panel. Furtherillustratively, the second portion of the secondary wall panel may beconfigured to engage a top edge of the main wall panel when the mainwall panel is in the deployed position. An inner surface of the secondportion of the secondary wall panel may be configured to engage and lieadjacent to an outer surface of the main wall panel when the main wallpanel is in the stowed position.

According to yet another aspect of the present disclosure, a rearaerodynamic drag reduction system configured to be coupled to a rearframe assembly of a trailer including a rear frame and a rear swing doorincludes a main wall panel configured to be pivotably coupled to avertical member of the rear frame to extend generally rearwardly of thetrailer at least partially along a height of the trailer, a secondarywall panel configured to be pivotably coupled to the rear swing door ofthe trailer to extend generally rearwardly of the trailer at leastpartially along a width of the trailer, a locking mechanism configuredto releasably lock the main wall panel and the secondary wall panel toeach other. The locking mechanism includes (i) a first portion coupleddirectly to the main wall panel to extend above the main wall panel and(ii) a second portion coupled directly to an inside surface of thesecondary wall panel. Illustratively, the main wall panel and thesecondary wall panel are movable relative to the rear frame assemblybetween deployed positions and stowed positions. Further, the firstportion of the locking mechanism is automatically received within a slotof the second portion of the locking mechanism when the main wall paneland the secondary wall panel are moved to their deployed positions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a rear end portion of a trailer showinga drag reduction system of the present disclosure including a rearfairing structure coupled to a rear frame of the trailer and shown inthe fully-deployed position when the rear doors of the trailer arefully-closed.

FIG. 2 is a perspective view similar to FIG. 1 showing the doors of thetrailer partially opened such that the rear fairing structure is onlypartially deployed as it moves toward a fully-closed, or retracted,position.

FIG. 3. is a perspective view similar to FIGS. 1 and 2 showing the doorsin an opened position (with one door removed in order to better view therear fairing structure) and showing the rear fairing structure retractedand positioned adjacent an outer surface of the door.

FIG. 4. is a perspective view similar to FIGS. 1-3 showing the doors ofthe trailer in a fully-opened position adjacent the sidewalls of thetrailer and showing the rear fairing structure in the retracted positionbetween the doors and the sidewalls of the trailer.

FIG. 5. is a perspective view of a portion of the drag reduction systemof the present disclosure including a locking mechanism to maintain therear fairing structure in a fully deployed position.

FIG. 6 is a schematic view of an alternative locking mechanism of therear drag reduction system.

FIG. 7 is a rear perspective view of a portion of an alternative dragreduction system showing an alternative hinge coupling the main wallmember to the rear swing door of the trailer to define a pivot axis ofthe main wall member that is offset from a pivot axis of the rear swingdoor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

For the purposes of promoting an understanding of the principles of theinvention, reference will now be made to illustrative embodiments shownin the attached drawings and specific language will be used to describethe same. While the concepts of this disclosure are described inrelation to a truck trailer, it will be understood that they are equallyapplicable to other vehicles generally, and more specifically toconventional flat-bed and/or box or van type trailers, examples of whichinclude, but should not be limited to, straight truck bodies, smallpersonal and/or commercial trailers and the like. Accordingly, thoseskilled in the art will appreciate that the present invention may beimplemented in a number of different applications and embodiments and isnot specifically limited in its application to the particularembodiments depicted herein.

Looking first to FIG. 1, a trailer 10 includes an aerodynamic rear dragreduction system 12 coupled to the rear frame assembly (including a rearframe 13 and rear doors 14 coupled to the rear frame 13) of the trailer10. Illustratively, the drag reduction system 12 operates to improve theaerodynamic efficiency of the trailer 10 by reducing drag and wind flowbehind the rear end of the trailer 10. In particular, the drag reductionsystem 12 operates to reduce airflow immediately behind the trailer 10as the trailer 10 is traveling down the road. As is discussed in greaterdetail below, the airflow immediately behind the rear end of the trailer10 is reduced because the drag reduction system 12 channels and controlsthe flow of air from the sides and top of the trailer 10 over the rearend of the trailer 10. This reduction of airflow behind the trailer 10may increase the fuel efficiency, or the efficiency of any other sourceof vehicle drive power, of the tractor/trailer combination.

Illustratively, the drag reduction system 12 extends behind the rearframe 13 and rear doors 14 of the trailer 10. As is further discussed inadditional detail below, the drag reduction system 12 is movable withthe rear doors 14 of the trailer 10 between a fully-deployed, or use,position, and a fully-closed, or storage position. As shown in FIGS. 1and 2, the trailer 10 includes a storage container 15 configured tocarry cargo therein. The storage container 15 includes sidewalls 11, afront end wall (not shown), the rear end frame assembly (including therear frame 13 and doors 14), a roof 22, and a floor assembly 24 whichall cooperate together to define an inside storage portion 25 of thecontainer 15 that is able to store various articles or goods therein.The trailer 10 further includes a rear wheel assembly, or bogie, 16, anda front support or landing gear (not shown) each coupled to the floorassembly 24 of the trailer 10. Illustratively, the floor assembly 24 ofthe trailer 10 includes various laterally-extending cross members (notshown) as well as longitudinally-extending floor boards 26. The frontend of the trailer 10 is configured to be coupled to a tractor (notshown) for towing the trailer 10 thereon, thus providing atractor-trailer assembly. It should be understood that while theaerodynamic drag reduction system 12 is shown for use with a trailer 10,the drag reduction system 12 may be coupled to any vehicle to reduce thedrag thereon.

Illustratively, the trailer 10 includes two drag reduction systems 12,as shown in FIG. 1. In particular, one system 12 is coupled to one rearswing door 14 of the trailer 10, while the other system 12 is coupled tothe other rear swing door 14 of the trailer 10. For the purposes of thedescription herein, however, only one drag reduction system 12 will bedescribed herein. However, it should be understood that the two dragreduction systems 12 of the trailer 10 are identical in configurationand function.

As shown in FIGS. 1 and 2, the drag reduction system 12 includes a mainwall panel 30 and a secondary wall panel 32. As shown in FIG. 1 anddiscussed in greater detail below, the main wall panel 30 is generallyvertically-oriented and is hingedly coupled to a vertical member 27 ofthe rear frame assembly 13 of the trailer 10. The auxiliary wall panel32 is adjacent the main wall panel 30 and is hingedly coupled to a topend of the swing door 14.

As shown in FIG. 1, the left main wall panel 30 of the first dragreduction system 12 is coupled to the left-most vertical member 27 ofthe rear frame 13 of the trailer 10 while the right main wall panel 30of the second drag reduction system 12 is coupled to the right-mostvertical member 27 of the rear frame 13 of the trailer 10.Illustratively, four hinges 29 are provided to pivotably couple the mainwall panel 30 to the rear frame 13. However, it should be understoodthat any suitable number of hinges may be used as well. Further, thehinge 29 may be any suitable hinge to allow for pivotable movement ofthe main and secondary wall panels 30, 32 such as, but not limited to, abutt hinge, a butterfly hinge, a living hinge, etc., in order to allowthe main wall panel 30 and the auxiliary wall panel 32 to hingedly moverelative to the rear frame assembly 13 of the trailer 30 along with apivot axis 53 defined by the hinges.

Illustratively, the pivot axis 53 of the main wall panel 30 is alignedwith the pivot axis of the rear swing door 14. As shown in FIG. 1, forexample, the rear swing door 14 is coupled to the rear frame 13 of thetrailer 10 by hinges 28. Hinges 29 of the main wall panel 30 arepositioned above and aligned with the hinges 28 for the rear swing door14 such that the rear swing door 14 and the illustrative main wall panel30 are configured to pivot about the same pivot axis 53. As is describedin detail below, however, the main wall panel 30 may be coupled directlyto the swing door 14 so that the main wall panel 30 pivots about an axisthat is offset from the pivot axis 53 of the rear swing door 14. Inother words, it should be understood that the pivot axis about which themain wall panel 30 pivots may be the same as or different from the pivotaxis about which the rear swing door 14 pivots.

As shown in FIG. 3, the main wall panel 30 includes a generallyrectangular body 34 defined by a top edge 36, a bottom edge 38, aninside edge 40, and an outside edge 42. Illustratively, the inside and doutside edges 40, 42 are parallel to each other and to the vertical post27 of the rear frame assembly 13. The bottom edge 38 generally extendshorizontally and is perpendicular to the inside and outside edges 40,42. As showing in FIG. 3, the outside edge 42 include a notice 44 formedtherein. As is discussed in greater detail below, the notice 44 operatesto provide an opening for the door locking mechanisms and/or handles(now shown) of the rear door 14 to allow the panel 30 to be able to liegenerally flat against an outer surface of the rear door 14 when in theclosed, or retracted, position. The top edge 36, however, is notparallel to the bottom edge 38 and is not perpendicular to the insideand outside edges 40, 42. Rather, the top edge 36 us angled relative tothe outer edges 38, 40, 42. Particularly, the top edge 36 is angleddownwardly from the outside edge 40 to the inside edge 42. It should beunderstood that while the top edge 36 is shown to be angled downwardly,it is within the scope of this disclosure for the top edge 36 to begenerally horizontal or angled upwardly as well. Further, it is withinthe scope of this disclosure to include a body 34 of the main wall panel30 defining inside and outside edges which are not parallel to eachother or to the vertical post 27 of the rear frame 13 to which the mainwall panel 30 is attached. As is discussed in greater detail below, thetop edge 36 of the panel 30 operates to support the secondary wall panel32 therefrom when the drag reduction system 12 is in the use position asshown, for example, in FIG. 1.

Illustratively, the body 34 of the main wall panel 30 extends below abottom edge 50 of the rear sill 52 of the rear frame 13 of the trailer10 such that the bottom edge 38 of the main wall panel 30 is positionedbelow the bottom edge 50 of the rear frame 13, as shown in FIGS. 1-4. Assuch, an overall length of the outside edge 40 of the main wall panel 30is longer than an overall length of the rear frame 13 of the trailer 10.Further, an overall length of the outside edge 40 of the main wall panel30 is greater than a height of the sidewall 11 of the storage container15 of the trailer 10. While the illustrative main wall panel 30 extendsbelow the rear frame 13, it should be understood that it is within thescope of this disclosure to include a main wall panel 30 having anysuitable length including one which does not extend below the rear frame13 of the trailer 10 and/or one which is generally equivalent in lengthto the rear frame 13 of the trailer 10.

As shown in FIGS. 1 and 2, the secondary wall panel 32 is coupled to atop portion of the rear swing door 14 and is configured to pivot aboutan axis 54 relative to the swing door 14. Illustratively, the secondarywall panel 32 includes a first portion 60 and a second portion 62hingedly coupled to the first portion 60. The first portion 60 iscoupled to the top portion of the swing door 14 and is configured toextend above a top edge 66 of the swing door 14. Illustratively, thefirst portion 60 extends generally upwardly to define a planar surfacegenerally parallel to the outer surface of the swing door 14. The secondportion 62 of the secondary wall panel 32 is coupled to the firstportion 60 via a hinged connection. As shown in FIGS. 1 and 2, and as isdiscussed in greater detail below, the second portion 62 is configuredto extend outwardly away from the first portion 60 and away from theswing door 14, as shown in FIG. 1 when the drag reduction system 12 isin the fully-deployed, or use, position. The second portion 62 is alsoconfigured to lie generally adjacent the first portion 60 such that theouter surface of the second portion 62 is generally parallel to thefirst portion 60, as shown for example in FIG. 3, when the dragreduction system 12 is in the stowed position.

Illustratively, the second portion 62 defines first and second outeredges 70, 72, a top edge 74, and a bottom edge 76. As shown in FIG. 2,the side edges 70, 72 converge toward each other from the top edge 74toward the bottom edge 76. Thus, a length of the bottom ledge 76 issmaller than a length of the top edge 74.

The drag reduction system 12 further includes an inner limit strap 80,shown in FIGS. 1 and 2. The inner limit strap 80 includes a first end 82coupled to an inner surface 83 of the main wall member 30 and a secondend 84 coupled to the outer surface 85 of the swing door 14. As isdescribed in greater detail below, the inner limit strap 80 operates tolimit the movement of the main wall panel 30 relative to the swing door14. In addition to the inner limit strap 80, the drag reduction system12 further includes an outer limit strap 90 having a first end 92coupled to an outer surface 93 of the main wall panel 30 and a secondend 94 coupled to the outer, vertical post 27 of the rear frame 13 ofthe trailer 10, as shown in FIGS. 1 and 2. As is discussed in greaterdetail below, the outer limit strap 90 also operates to limit movementof the main wall panel 30 relative to the swing door 14. In particular,the inner limit strap 80 operates to prevent outward swinging movementof the main wall panel 30 relative to the swing door 14 beyond apredetermined angle while the outer limit strap 90 operates to preventinward swinging movement of the main wall panel 30 relative to the swingdoor 14 beyond a predetermined angle. The length of the limit straps 80,90 may be made variable in order to selectively change the predeterminedangle beyond which the door 14 is unable to swing (both outwardly andinwardly).

In use, as noted above, the drag reduction system 12 operates toincrease aerodynamic efficiencies of the trailer 10 to which it isattached by smoothing the airflow behind the rear frame 13 of thetrailer 10 as the trailer 10 travels along a highway, for example.Illustratively, the drag reduction system 12 is movable between afully-deployed position, as shown in FIG. 1, and a retracted, or closed,position, as shown in FIGS. 3 and 4. In the fully-deployed position, thedrag reduction system 12 is operable to reduce the drag of the trailer10 as the trailer 10 travels along a highway, for example. As shown inFIG. 1, the main wall panel 30 extends outwardly away from the rearframe 13 of the trailer 10. Illustratively, the plane defined by themain wall panel 30 is neither parallel to nor perpendicular to a planedefined by the sidewall 11 of the trailer 10. The main wall panel 30 issimilarly neither parallel to nor perpendicular to a plane defined bythe rear frame 13. In other words, the main wall panel 30 is angledrelative to the sidewall 11 of the trailer 10 and is angled relative tothe rear frame 13 of the trailer 10. While the main wall panel 30 of thedrag reduction system 12 is illustratively shown to be angled relativeto the rear frame 13 by a particular degree, it should be understood,that it is within the scope of this disclosure to angle the main wallpanel 30 relative to the rear frame 13 by any suitable degree.

In the fully-deployed position, the inner limit strap 80 and the outerlimit strap 90 cooperate to maintain the main wall panel 30 in thedeployed position. As noted above, the inner limit strap 80 operates toprevent the main wall panel 30 from pivoting outwardly about the axis 53relative to the rear frame 13 beyond a certain predetermined positionwhile the outer limit strap 90 operates to prevent the main wall panel30 from pivoting inwardly about the axis 53 relative to the rear frame13 beyond a certain predetermined position. Illustratively, the innerand outer limit straps 80, 90 may be made from any suitable, flexible orbendable, but generally non-elastic material. Further, while only oneinner strap 80 and one outer strap 90 are shown, it is within the scopeof this disclosure to include any number of inner and/or outer strapsfor maintaining the deployed position of the main wall panel 30.Further, it is within the scope of this disclosure for the dragreduction system 12 to include devices other than the inner and outerstraps 80, 90 for maintaining the deployed position of the main wallpanel 30. In other words, other stops or limiters may be coupled to themain wall panel 30 in order to prevent outward movement of the main wallpanel 30 relative to the swing door 14 of the trailer 10 beyond acertain predetermined position and to prevent inward movement of themain wall panel 30 relative to the rear frame 13 and the rear swing door14 beyond a certain predetermined position.

Looking still to FIG. 1, the secondary panel 32 of the drag reductionsystem 12 extends outwardly from the rear swing door 14 of the trailer10 when the system 12 is in the deployed position. Illustratively, aninner surface of the secondary panel 32 rests upon the top edge 36 ofthe main wall panel 30 when in the deployed position. As noted above,the top edge 36 of the main wall panel 30 is angled downwardly. As such,the secondary panel 32 is angled slightly downwardly as well. In otherwords, a plane defined by the second portion 62 of the secondary panel32 is not parallel to a top surface of the roof assembly 22 of thetrailer 10. Rather, the second portion 62 is angled downwardly.

When the drag reduction system 12 is in the deployed position, the swingdoors 14 of the trailer 10 are closed. The main and secondary wallpanels 30, 32 of each of the two drag reduction systems 12 extendoutwardly from the rear frame 13 and rear swing doors 14 in order todirect and smooth air flow around the rear end of the trailer 10 as thetrailer 10 travels down the highway, for example. The inner and outerlimit straps 80, 90 maintain the position of the main wall panels 30 ofeach drag reduction system 12 while the second portion 62 of thesecondary panel 32 rests upon the top edge 36 of the main wall panel 30of each respective system 12.

When the trailer 10 is not traveling on the road and it is necessary fora user or operator to open the rear doors 14 of the trailer 10 in orderto gain access to the storage area 25 of the storage container 15, theuser need only open the doors 14 in the usual or typical manner and thedrag reduction system 12 coupled to each door 14 automatically moves toits closed position, as shown in FIGS. 2-4. Looking to FIG. 2, as theswing door 14 is opened, the swing door 14 is moved toward the main wallpanel 30 while the main wall panel 30 remains generally stationaryrelative to the trailer 10. As the swing door 14 is moved closer to themain wall panel 30, the bottom surface of the second portion 62 of thesecondary panel 32 remains engaged with the top surface 36 of the mainwall panel 30. Once the outer surface 85 of the swing door 14 engagesthe inner surface of the main wall panel 30, the top edge 36 of the mainwall panel 30 no longer supports the second portion 62 of the secondarypanel 32. Thus, the second portion 62 of the secondary panel 32 pivotsdownwardly about the axis 54 such that the bottom surface of the secondportion 62 of the secondary panel 32 is engaged with the outer surfaceof the main wall panel 30. During movement of the swing door 14 towardthe main wall panel 30, the inner limit strap 80 collapses such thatthere is not tension on the inner limit strap 80, as shown in FIG. 2.Looking to FIG. 4, once the door 14 is moved to the fully-openedposition, the drag reduction system 12 is in the closed, or retracted,position and is located between the outside surface of the swing door 14and the sidewall 11 of the trailer 10. The outside surface of the mainwall panel 30 and the outside surface of the second portion 62 of thesecondary panel 32 are each engaged with the sidewall 11 of the trailer10. The inner surface of the main wall panel 30 is engaged with theouter surface 85 of the swing door 14.

In order to move the drag reduction systems 12 to the opened, ordeployed, position, the user or operator need only move the doors 14 ofthe trailer 10 from their fully-opened position back to theirfully-closed position, shown in FIG. 1. In use, therefore, as the doors14 are closed, the drag reduction system 12 associated with each door 14is automatically moved to the deployed position. In particular, as theswing door 14 is moved from the fully-opened position shown in FIG. 4toward the closed position shown in FIG. 1, the drag reduction system 12associated therewith moves with the door 14. As noted above, thesecondary wall panel 32 is coupled to the door 14 for movementtherewith. Further, when the drag reduction system 12 is in thefully-closed position (and the door 14 is in an opened position), thesecondary wall panel 32 is positioned over the main wall panel 30 suchthat the secondary wall panel 32 moves with the door 14 as the door 14is moved from the opened position to the closed position. As such, themain wall panel 30 is also urged to move with the door 14 because thesecondary panel 32 covers the main panel 30 and carries it therewith.

As the door 14 is further moved toward the closed position and once themain wall panel 30 reaches the predetermined deployed position, theouter limit strap 90 prevents further movement of the main wall panel 30with the door 14. As the door 14 is further moved toward the closedposition, the main wall panel 30 remains generally stationary and thesecond portion 62 of the secondary wall panel 32 begins to pivotupwardly about the pivot axis 54. The second portion 62 is urged topivot upwardly because as the secondary wall panel 32 continues to movewith the door 14 as the door 14 moves to the closed position, the bottomsurface of the second portion 62 of the secondary wall panel 32 remainssupported by the top edge 36 of the main wall panel 30 and moves alongthis top edge 36 of the main wall panel 30 while the main wall panel 30remains relatively stationary. As such, the second portion 62 of thesecondary wall panel 32 is moved upwardly to the deployed position shownin FIG. 1.

In other words, it is not necessary to perform an extra step to move thedrag reduction system 12 to the closed position prior to opening thetrailer doors 14 or to move the drag reduction system 12 to the openedposition after closing the door 14. Rather, the drag reduction system 12automatically moves to the closed position upon opening the door 14 towhich the drag reduction system 12 is attached and moving the door 14 tothe fully opened position along the sidewall 11 of the trailer 10, asshown in FIG. 4. It should be understood that the drag reduction systems12 of the present disclosure may be used alone or in conjunction withother drag reduction systems such as, for example, aerodynamic sideskirts such as those disclosed in U.S. Pat. Nos. 8,177,286 and8,783,758, for example, the entirety of each of which is incorporatedherein by reference.

Illustratively, each wall panel 30, 32 is made of a composite material.For example, the composite material may include a plastic core and metalouter skins coupled to the plastic core. Such a composite materialprovides a rigid, but lightweight and durable material. Illustratively,for example, each wall panel 30, 32 may be made of a DURAPLATE®composite panel provided by Wabash National Corporation of Lafayette,Ind. DURAPLATE® composite panels are constructed of a high-densitypolyethylene plastic core bonded between two high-strength steel skins.

The inner and outer skins respectively may be formed of a metal ormetallic composition, examples of which include, but should not belimited to aluminum, galvanized steel, full hardened steel, such as AISIGrade E steel, or the like. In one illustrative embodiment, for example,the outer skin is formed of ASTM G90 galvanized steel, and the innerskin is formed of ASTM G40 galvanized steel. In alternative embodiments,the inner and/or outer skins respective may be formed of other rigid,semi-rigid, metallic or non-metallic materials. Illustratively, thecomposite material (i.e., panels 30, 32) is approximately between 0.08inch and 0.20 inch thick, with a preferred thickness of approximately0.10 inch thick. While the illustrative panels 30, 32 disclosed hereinare each made of the particular composite material described above, itshould be understood that other suitable composite materials may be usedas well. For example, the panels 30, 32 may also be made from a plasticpultrusion with fiber reinforcements embedded inside the polymermaterial. The reinforcement fibers may be made from glass, carbon,and/or other suitable materials, for example.

It should be further understood that while the illustrative panels 30,32 disclosed herein are made from a composite, the panels 30, 32 mayalternatively be formed from a non-composite material such as a sheetmade from a metal, metal alloy, or plastic, for example. The panels 30,32 may be made from ferrous or nonferrous materials including plasticsor composites incorporating a combination of ferrous and/or nonferrousmaterials therein. In particular, an alternative panel (not shown) maybe made from galvanized steel. Of course, it is within the scope of thisdisclosure to include non-galvanized steel sheets, or other suchnon-composite panels, of any suitable thickness as well.

Looking now to FIG. 5, the rear drag reduction system 12 includes alocking mechanism 100. The locking mechanism 100 includes a groovedlatch (or second portion) 102 coupled to an inner, or bottom, surface104 of the secondary panel 32 and a pin (or first portion) 106 coupledto an inner surface 108 of the main wall panel 30. The pin 106 iscoupled near the top edge 36 of the main wall panel 30 near the rear, ortrailing, edge 42 of the main wall panel 30. The pin 106 includes aboss, or head, 110 having a diameter larger than a body 112 of the pin106. Illustratively, the body 112 of the pin 106 is angled and a bottomportion of the body 112 is coupled to the wall panel 30 by fastenerssuch as screws 114, for example. The grooved latch 102 includes a slot,or groove, 116 configured to receive the head 110 of the pin 106 thereinin order to limit the main panel 30 vertically and in one directionlaterally. The grooved latch 102 is similarly coupled to the secondarypanel 32 by fasteners such as screws 114 for example. Other fastenerssuch as nails, bolts, and/or adhesives, for example, may be used aswell. When the rear drag reduction system 12 is moved to thefully-opened position, the head 110 of the pin 106 is received withinthe groove 116 of the latch 102 to maintain the relative position of thepanels 30, 32 to each other. As the rear drag reduction system 12 ismoved to the fully-closed position, the pin 106 is automatically movedout of the groove 16 as the swing doors 85 of the trailer 10 are openedin order to allow the panel 32 to fold over the panel 30.

Looking now to FIG. 6, an alternative locking mechanism 200 is providedwherein the secondary panel 32 includes an outer edge feature, such asthe latch or hook, 202 which may be integrally molded with the secondarypanel 32, stamped into the secondary panel 32, formed with the secondarypanel 32, or coupled to the secondary panel 32 as a separate component.The hook 202 defines a generally J-shaped profile and includes a baseportion 206 coupled to the secondary panel 32 and a downwardly-extendinghook 208 which when brought into contact with the main panel 30 servesto engage the main panel 30, or a portion of the main panel 30, in orderto limit the movement of the main panel 30 vertically and in onedirection laterally. Illustratively, the hook 208 defines a slot 210.

The main panel 30 also includes a mating feature, such as the hook, 204which may also be integrally molded, stamped, or formed with the mainpanel 30, or may be separately formed and then coupled to the main panel30 as a separate component. The hook 204 of the main panel 30 similarlyincludes a base portion 212 coupled to the main panel 30 and anupwardly-extending hook, or pin, 214 which engages the hook 202 of thesecondary panel 32 when the rear drag reduction mechanism 12 is in thefully-opened position. In an alternative embodiment (not shown), themating shapes may be triangular, curved, or faceted in any suitablegeometry that allows the two panels 30, 32 to become matingly-engagedwith one another. As the rear drag reduction system 12 is moved to thefully-opened position, the bottom hook portion 214 is received withinthe sot 210 of the upper hook portion 208 while the upper hook portion208 is received within a slot 216 of the bottom hook portion 214. As therear drag reduction system 12 is moved to the fully-closed position, thebottom hook portion 214 is automatically removed from within the slot210 of the upper hook portion 208, and the upper hook portion 208 isremoved from within the lower slot 216, as the swing doors 14 of thetrailer 10 are opened in order to allow the panel 32 to fold over thepanel 30.

Illustratively, while the various locking mechanism embodiments havebeen shown in figures and described above, it should be understood thepresent disclosure includes any locking mechanism including a firstportion, such as the illustrative pin 106 and illustrative hook 204,coupled to or integrally formed with one of the main wall panel 30 andthe secondary wall panel 32. This first portion may extend upwardlyabove the top edge 36 of the main wall panel 30, or below a bottomsurface of the secondary panel 32, and is configured to engage a secondportion, such as the illustrative latch 102 and illustrative hook 202,coupled to or integrally formed with the other one of the main wallpanel 30 and the secondary wall panel 32. In other words, the componentsof the locking mechanisms described herein may be coupled to either themain wall panel 30 and the secondary wall panel 32 such that each panel30, 32 includes one component of the locking mechanism that isreleasably coupled with a mating component of the locking mechanism thatcoupled to the other panel 30, 32.

As discussed above, the illustrative main wall panel 30 shown in FIGS.1-5 is coupled to the vertical member 27 of the rear frame 13 of thetrailer 10 by a plurality of hinges 29. Further, the rear swing door 14is also coupled to the vertical member 27 of the rear frame 13 of thetrailer 10 by a plurality of hinges 28, shown in FIG. 1, that arealigned with the hinges 29 to define the same pivot axis 53 about whichboth the rear swing door 14 and the main wall panel 30 pivot.Alternatively, as shown in FIG. 7, however, the main wall panel 30 maybe coupled to the rear swing door 14 of the trailer by an alternativehinge 129. The alternative hinge 129 includes a first hinge plate 130coupled to the inner surface 83 of the main wall panel 30, a secondhinge plate 131 coupled to an outer surface of the rear swing door 14near the vertical member 27 of the rear frame 13 of the trailer 10, anda hinge portion between the first and second hinge plate 130, 131 whichdefines a pivot axis 153 offset from the pivot axis 53 of the hinge 29coupling the rear swing door 14 to the rear frame 13 of the trailer 10.Illustratively, the alternative hinge 129 further includes a mountingplate 132 positioned between the second hinge plate 131 and the outsidesurface of the rear swing door 14. It should be understood that whilethe particular hinge 129 is shown in FIG. 7, any suitable hinge may beprovided which allows for pivotable movement of the main wall panel 30that is offset from the pivot axis 53 of the hinges 29 for the rearswing door 14 in order to allow the main wall panel 30 to hingedly moverelative to the rear frame assembly 13 of the trailer.

As is further shown in FIG. 7, the main wall panel 30 includes a cut-outportion 150 formed on an inside edge of the main wall panel 30. Thecut-out portion 150 is formed to cooperate with the hinge 28 couplingthe rear swing door 14 to the rear frame 13 of the trailer 10. Thecut-out portion 150 allows the main wall panel 30 to pivot about axis153 around the hinge 28 without interfering with the hinge 28 for therear swing door 14.

While the invention has been illustrated and described in detail in theforegoing drawings and description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly illustrative embodiments thereof have been shown and described andthat all changes and modifications that come within the spirit of theinvention are desired to be protected.

What is claimed is:
 1. A rear aerodynamic drag reduction systemconfigured to be coupled to a rear frame assembly of a trailer includinga rear frame and a rear swing door, the drag reduction systemcomprising: a main wall panel configured to be coupled to the rear frameassembly to extend generally rearwardly of the trailer at leastpartially along a height of the trailer, wherein the main wall panel ismovable relative to the rear frame assembly between a deployed positionand a stowed position; a secondary wall panel configured to be movablycoupled to the rear swing door of the trailer to extend generallyrearwardly of the trailer at least partially along a width of thetrailer, wherein the secondary wall panel is movable relative to therear frame assembly between a deployed position and a stowed position;and a locking mechanism configured to releasably couple the main wallpanel and the secondary wall panel to each other to prevent relativemovement between the main wall panel and the secondary wall panel whenthe main and secondary wall panels are in their deployed positions. 2.The rear aerodynamic drag reduction system of claim 1, wherein the mainwall panel is configured to be pivotably coupled to the rear frameassembly, and the secondary wall panel is configured to be pivotablycoupled to the rear swing door.
 3. The rear aerodynamic drag reductionsystem of claim 2, wherein the main wall panel is configured to bepivotably coupled to the rear swing door of the rear frame assembly, andwherein the main wall panel is configured to pivot about an axis offsetfrom an axis about which the rear swing door pivots.
 4. The rearaerodynamic drag reduction system of claim 2, wherein the main wallpanel is configured to be pivotably coupled to a vertical member of therear fame of the rear frame assembly, and wherein the main wall panel isconfigured to pivot about an axis aligned with an axis about which therear swing door pivots.
 5. The rear aerodynamic drag reduction system ofclaim 1, wherein the locking mechanism includes a first portion coupledto the main wall panel and a second portion coupled to the secondarywall panel, and wherein the first and second portions are configured toreleasably engage each other.
 6. The rear aerodynamic drag reductionsystem of claim 1, wherein the locking mechanism includes (i) a latchcoupled to the one of the main wall panel and the secondary wall panel,the latch defining a slot, and (ii) a pin coupled to the other of themain wall panel and the secondary wall panel, and wherein the pin isreceived within the slot when the main and secondary wall panels are intheir deployed positions.
 7. The rear aerodynamic drag reduction systemof claim 6, wherein the latch is coupled to an inner surface of thesecondary wall panel and the pin is coupled to an inner surface of themain wall panel.
 8. The rear aerodynamic drag reduction system of claim7, wherein the latch is adjacent outer and bottom edges of the secondarywall panel and wherein the pin is adjacent the rear and top edges of themain wall panel.
 9. The rear aerodynamic drag reduction system of claim7, wherein the pin includes a head received within the slot when themain and secondary wall panels are in their deployed positions, and abody coupled to the inner surface of the main wall panel.
 10. The rearaerodynamic drag reduction system of claim 9, wherein the body of thepin includes an upper portion offset from a lower portion.
 11. The rearaerodynamic drag reduction system of claim 6, wherein the latch isintegrally formed with the secondary wall panel and the pin isintegrally formed with the main wall panel.
 12. The rear aerodynamicdrag reduction system of claim 6, wherein the latch extends downwardlybelow an inner surface of the secondary wall panel and the pin extendsupwardly above a top edge of the main wall panel.
 13. The rearaerodynamic drag reduction system of claim 1, wherein the lockingmechanism is automatically moved to a locked position when a user movesthe rear swing door to a fully-closed position, and the lockingmechanism is automatically moved to an unlocked position when a usermoves the rear swing door to a fully-opened position.
 14. The rearaerodynamic drag reduction system of claim 13, wherein the main wallpanel is automatically moved to the deployed position when a user movesthe rear swing door to a fully-closed position, and wherein the mainwall panel is automatically moved to the stowed position when a usermoves the rear swing door to a fully-opened position.
 15. A rearaerodynamic drag reduction system configured to be coupled to a rearframe assembly of a trailer including a rear frame and a rear swingdoor, the drag reduction system comprising: a main wall panel configuredto be coupled to a vertical member of the rear frame to extend generallyrearwardly of the trailer at least partially along a height of thetrailer; a secondary wall panel configured to be coupled to the rearswing door of the trailer to extend generally rearwardly of the trailerat least partially along a width of the trailer; and a locking mechanismhaving a first portion coupled directly to the main wall panel and asecond portion coupled directly to the secondary wall panel, wherein thefirst and second portions of the locking mechanism are coupled to eachother when the main wall panel and the secondary wall panel areconfigured to extend rearwardly of the trailer.
 16. The rear aerodynamicdrag reduction system of claim 15, wherein the main wall panel ismovable between a deployed position and a stowed position, wherein thesecondary wall panel is movable between a deployed position and a stowedposition, wherein the main wall panel is automatically moved to thedeployed position and the first and second portions of the lockingmechanism are automatically engaged with each other when a user movesthe rear swing door to a fully-closed position.
 17. The rear aerodynamicdrag reduction system of claim 16, wherein the first and second portionsof the locking mechanism are automatically disengaged with each other asthe main and secondary wall panels are moved to the stowed position. 18.The rear aerodynamic drag reduction system of claim 15, wherein thesecondary wall panel includes a first portion configured to be coupledto a top of the rear swing door and a second portion pivotably coupledto the first portion for movement about an axis parallel to a top edgeof the rear swing door, and wherein the second portion of the lockingmechanism is coupled to the second portion of the secondary wall panel.19. The rear aerodynamic rear drag reduction system of claim 18, whereinthe second portion of the secondary wall panel is configured to engage atop edge of the main wall panel when the main wall panel is in thedeployed position, and wherein an inner surface of the second portion ofthe secondary wall panel is configured to engage and lie adjacent to anouter surface of the main wall panel when the main wall panel is in thestowed position.
 20. A rear aerodynamic drag reduction system configuredto be coupled to a rear frame assembly of a trailer including a rearframe and a rear swing door, the drag reduction system comprising: amain wall panel configured to be pivotably coupled to a vertical memberof the rear frame to extend generally rearwardly of the trailer at leastpartially along a height of the trailer; a secondary wall panelconfigured to be pivotably coupled to the rear swing door of the trailerto extend generally rearwardly of the trailer at least partially along awidth of the trailer; and a locking mechanism configured to releasablylock the main wall panel and the secondary wall panel to each other, thelocking mechanism having (i) a first portion coupled directly to themain wall panel to extend above the main wall panel and (ii) a secondportion coupled directly to an inside surface of the secondary wallpanel, wherein the main wall panel and the secondary wall panel aremovable relative to the rear frame assembly between deployed positionsand stowed positions, and wherein the first portion of the lockingmechanism is automatically received within a slot of the second portionof the locking mechanism when the main wall panel and the secondary wallpanel are moved to their deployed positions.